Mattress having three separate adjustable pressure relief zones

ABSTRACT

A support having adjustable pressure relief zones comprising at least three pressure zones, each having an adjustable pressure relief valve operatively attached to each of the at least three pressure zones. There is at least one cell in a first zone having a first effective fluid volume and at least one cell in a second zone having a second effective fluid volume adjustable to greater than said first effective fluid volume. The greater effective fluid volume is associated with supporting a greater load associated with that said zone and the lower fluid volume is for greater responsiveness.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention is a continuation-in-part of application Ser. No. 09/295,139 filed Apr. 20, 1999, now U.S. Pat. No. 6,269,505 (issued Aug. 7, 2001) and application Ser. No. 11/056,686 filed Feb. 11, 2005. The contents of both applications are incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to an adjustable inflatable cushioning device for body supports such as a mattress, sofa, or chair cushion having separate pressure zones.

BACKGROUND OF THE INVENTION

Inflatable cushioning devices for use with body supports, such as a mattress, sofa, seat, or the like may included a plurality of air cells or bladders that are inflated to support a person. The air cells provide support to the person, and can be inflated to a desired pressure level to provide the person with a predetermined level of comfort and support.

Air cushion devices may require an external pump to inflate the air cells in the device. Alternatively, the air cushion devices are pre-inflated in the manufacturing plant and are shipped to a field location for use. A problem may develop when the atmospheric pressure at the inflation location is different from the atomospheric pressure at the field location where the device is used. For example, if the field location atmospheric pressure is lower than the atmospheric pressure at the inflation location, the air cells in the field will expand and become firmer.

SUMMARY OF THE INVENTION

A first embodiment of the invention is a support having adjustable pressure relief zones comprising: at least three pressure zones; an adjustable pressure relief valve operatively attached to each of the at least three pressure zones; at least one cell in a first zone having a first effective fluid volume; and at least one cell in a second zone having a second effective fluid volume adjustable to greater than said first effective fluid volume, wherein the greater effective fluid volume is associated with supporting a greater load associated with that said zone.

A second embodiment of the invention is a mattress comprising: a first pressure zone having a first cell volume; a second pressure zone having a second cell volume operatively positioned with respect to said first pressure zone; a third pressure zone having a third cell volume operatively positioned with respect to said second pressure zone; and a dial positioned on each of the pressure zones to adjust an individual zone pressure.

A third embodiment of the invention is a mattress comprising: a first zone having a first fluid volume; a second zone having a second fluid volume operatively positioned with respect to said first zone; a third zone having a third fluid volume operatively positioned with respect to said second zone; an adjustable pressure valve in each of said zones; a resilient border surrounding said zones; and a cover encompassing said border and said zones.

A forth embodiment of the invention is a support surface comprising: a first zone having a port on each cell, a conduit attached to said ports, said conduit operatively attached to an intake check valve and a pressure relief valve; a second zone having an intake check valve on each cell, and an exhaust check valve on each cell that is attached to a common exhaust manifold, said exhaust manifold operatively attached to a pressure relief valve, wherein the second zone is operatively positioned with respect to said first zone; a third zone having a port on each cell, a conduit attached to each said port, said conduit operatively attached to an intake check valve and a pressure relief valve, wherein the third zone is operatively positioned with respect to said second zone; a first fluid cell volume associated with at least one of said zones; and a second fluid cell volume associated with at least one of said zones, wherein said second fluid cell volume is greater than said first fluid volume and wherein second fluid volume supports a greater load per square inch of a surface of said zone.

A fifth embodiment of the invention is a support surface comprising: a first zone having a single port on each cell, a first conduit attached to said ports, said first conduit operatively attached to an intake check valve and a pressure relief valve; a second zone having an intake check valve on each cell, and a port on each cell that is attached to a second conduit, said second conduit operatively attached to a pressure relief valve, wherein the second zone is operatively positioned with respect to said first zone; a third zone having a single port on each cell, a third conduit attached to each said port, said conduit operatively attached to an intake check valve and a pressure relief valve, wherein the third zone is operatively positioned with respect to said second zone; and a conduit crossover check valve allowing one way flow from the third conduit to the second conduit, wherein crossover flow to the second conduit refills fluid cells if cell pressure is below a pressure relief set point of each of the pressure relief valves of the second and third conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention will best be understood from a detailed description of the invention and a preferred embodiment thereof selected for the purposes of illustration and shown in the accompanying drawings in which:

FIG. 1 illustrates a perspective view of an inflatable cushioning device of the present invention;

FIG. 2 illustrates a partial top view of a support including three zones;

FIG. 3 illustrates a cross-sectional view of a fluid cell;

FIG. 4 illustrates a cross-sectional view of another embodiment of the fluid cells for zones having quicker response;

FIG. 5 illustrates a cross-sectional view of reactive fluid cell for a zone in the support;

FIG. 6 illustrates an example of a plurality of zones in the support apparatus with cells arranged in different orientations;

FIG. 7 illustrates the different forces associated with each zone;

FIG. 8 illustrates the pressure being equalized in each zone for the patient;

FIG. 9 illustrates a support apparatus having zones that comprises fluid cells with different reactivity;

FIG. 10 illustrates a fluid cell with a spring;

FIG. 1 illustrates an example of an individual mattress cushioning device;

FIG. 12 illustrates an individual zone pressure control apparatus;

FIG. 13 illustrates a mattress having three adjustable pressure zones having different reactivity rates;

FIG. 14 illustrates a cross-sectional view of one type of fluid cell that may be present in the device of the present invention;

FIG. 15 illustrates a perspective view of a support comprising a plurality of cells;

FIG. 16 illustrates a helical fluid support cell;

FIG. 17 illustrates a top view of a resilient support;

FIG. 18 illustrates a bottom view of a resilient support;

FIG. 19 illustrates a side view of a support zone;

FIG. 20 illustrates a side view of a helical fluid cell;

FIG. 21 illustrates a bottom view of a fluid cell;

FIG. 22 illustrates a mattress having three adjustable pressure zones having different reactivity rates and center section with each fluid cell having intake and exhaust check valves; and

FIG. 23 illustrates a mattress having three adjustable pressure zones having different reactivity rates and a center section with each fluid cell having an intake check valve and a port.

DETAILED DESCRIPTION OF THE INVENTION

Although certain preferred embodiments of the present invention will be shown and described in detail, it should be understood that various changes and modifications may be made without departing from the scope of the appended claims. The scope of the present invention will in no way be limited to the number of constituting components, the materials thereof, the shapes thereof, the relative arrangement thereof, etc., and are disclosed simply as an example of the preferred embodiment. The features and advantages of the present invention are illustrated in detail in the accompanying drawings, wherein like reference numerals refer to like elements throughout the drawings. Although the drawings are intended to illustrate the present invention, the drawings are not necessarily drawn to scale.

The present invention may provide a cushioning device for a mattress, seat, sofa, or the like where support is obtained from a fluid such as atmospheric air. The cushioning device has few moving parts, is user controllable, requires minimal maintenance, and is easily repairable. The cushioning device of the present invention may include a support system apparatus, a sleeve apparatus, a jacket, a topper cushion, and an outer cover.

The support system apparatus may include at least three support cells for providing lifting support for a body and having different zones with individual response rates tailored to weight. Each support cell in a zone may include an envelope containing a volume of fluid to match the anticipated weight supported to tailor the reactivity of the zone. Application of an external load on an outer surface of the envelope causes the envelope to deform into a compressed form. The envelope includes a reforming element that is capable of providing a reforming force to the interior surface of the envelope, to return the envelope to its original unloaded form. The reforming element is preferably made from a resilient foam material; however, other resilient means can be used.

An intake valve and an exhaust valve also may be included in each support cell within the zones. The exhaust valve in each support cell may be connected to a pressure control system to control the firmness of each zone. The intake valve in each support cell may be connected to an intake control system or draw fluid directly from the atmosphere. Each intake valve may include an intake check valve allowing fluid to flow into the support cell, while preventing fluid from flowing out of the support cell. Each exhaust valve includes an exhaust check valve allowing fluid to flow out of the support cell, while preventing fluid from flowing into the support cell. The intake control system may be connected to a fluid supply reservoir. The exhaust control system may also be connected to a fluid exhaust reservoir. The fluid included in the supply and exhaust reservoirs may be air, however, any suitable fluid, e.g., water or nitrogen can be used. The fluid supply and exhaust reservoirs may comprise the same reservoir, and may comprise an ambient source of fluid such as atmospheric air.

In use, the weight of a body of a person, patient, or animal resting on the envelope deforms the envelope or cells in each zone. For illustration purposes, a patient will be used as an example of a body resting on the envelope. The pressure of the fluid within the envelope increases as the volume of the envelope decreases under deformation. As the pressure of the fluid increases, the fluid in the envelope flows out of the envelope through the exhaust valve and into the exhaust control system. The individual zones are tailored so that the lightest weight of a patient is coordinated with a fluid cell having the lowest volume for the quickest removal of excess fluids. Next, the fluid may flow from the exhaust control system into the fluid exhaust reservoir. Furthermore, as the envelope deforms to conform to the irregular shape of the patient, the area of the envelope supporting the load increases. Equilibrium may be achieved when the forces within the envelope, including the pressure of the fluid within the envelope multiplied by the area of the envelope supporting the load, plus the force provided by the reforming element equal the weight of the load.

A controllable pressure relief valve is included in each zone so that a maximum or minimum pressure level of the fluid within the envelope can be set and maintained. Different selected maximum pressure levels of the fluid in the separate zones allow the support cell to accommodate different weights or allow different degrees of conformation between the patient and the envelope surface. The maximum pressure level of the fluid may be set to ensure that the interface pressure under the entire contact surface of the patient is below the pressure that may cause soft tissue damage such as pressure sores to occur. The pressure relief valve may be a mechanical device such as unidirectional, spring-loaded ball check valve that allows instant release of the excess fluid when pressure is exceeded without the requirement of power. The release pressure of the mechanical pressure relief valve can be adjusted by raising or lowering the spring tension of the valve for example by moving the seat of the spring with respect to the ball to change the spring pre-load.

As the weight of the patient is removed from the support cell, the reforming element exerts an outward force on the interior surface of the envelope. As the envelope expands, a partial vacuum is created in the interior space of the envelope, causing fluid to be drawn back into the interior space of the envelope. The fluid may be drawn from the fluid supply reservoir or directly from the atmosphere into the intake control system, through the intake valve, and into the interior space of the envelope. The intake valve may include a one way intake check valve that permits fluid to re-enter the interior space of the envelope, while preventing fluid from exiting the interior space of the envelope.

The support cells included in the present invention may use atmospheric pressure as the pressure source for inflation. Therefore, when the fluid supply and exhaust reservoirs comprise atmospheric air, inflation can be accomplished without the need for expensive blowers, pumps or microprocessors as required by previously available “treatment products.” A plurality of support cells can be interconnected with the intake control system and the exhaust control system to create a support system apparatus. The support system apparatus may support a patient by providing self adjusting pressure management to the entire contact surface of the patient. The support system apparatus provides a low interface pressure under the entire surface of the patient being supported. For example, if the patient is lying on the support system apparatus, the support system apparatus ensures that the interface pressure under the entire contact surface of the patient is below the pressure that may cause soft tissue damage to occur.

The support system apparatus also has the ability to self-adjust every time a patient moves, or is repositioned on the support system apparatus. When the pressure distribution applied to the support system apparatus changes, the support cells within the support system apparatus automatically inflate or deflate as necessary, to maintain a low interface pressure under the entire patient.

Another embodiment of the current invention provides for separately controlled responsiveness of the support zones within the support system apparatus. Each support zone comprises at least one support cell. Each support cell includes at least one intake valve and at least one exhaust valve. The intake valve for each support cell in each support zone is connected to the intake control system. The exhaust valves from each support cell in a single support zone may be connected to a single exhaust control system. Each support zone may have a separate exhaust control system. The intake control system may be connected to the fluid supply reservoir. The exhaust control system for each support zone may be connected to the fluid exhaust reservoir. Generally the pressure level in each support zone is set at a different level for comfort. The reactiveness of each support zone can be adjusted by modifying the amount of restriction adjacent the exhaust valve of each zone thus modifying the speed at which excess pressure is vented. For example, if the support system apparatus comprises a mattress in a bed, the upper, middle, and lower zones of the support system apparatus can be set to provide a different level of responsiveness for the upper, middle, and lower portions of the patient's body by adjusting how quickly the zones reach the set pressure. Thus for example, two identical mattresses could be set to the have the same maximum pressure in each zone, but one would have a fast response to movement and the other would have a slow or delayed response and would provide a firmer feel during patient movement even with the exact same pressure settings based solely on the setting of the adjustable restrictor placed in line before the pressure relief valve outlet and the zone.

The sleeve apparatus may includes a cell cover surrounding each support cell. For a plurality of support cells, each cell cover may be attached to an adjacent cell cover. The cell cover may allow the surface of the envelope of the support cell to slide freely along a first side of the cell cover, without transmitting this sliding movement to a second side of the cell cover. The second side of the cell cover may be the side on which a patient is lying. The movement of the support cell may not be transmitted to the patient, thereby preventing frictional or shear force abrasion damage to the skin of the patient. In the event that repair of a support cell becomes necessary, the sleeve apparatus allows each support cell to be easily removed and replaced.

The topper cover may provide further resilient torso support. The topper cover may be formed from a layered fiber filled material or other suitable material. The topper may include a resilient heel support unit to reduce pressures on the sensitive heel region of a patient. The topper cover may rest above the jacket, and may be covered by the outer cover. Alternatively, the topper cover may rest above the support system apparatus.

The outer cover provides a low friction and low shear surface further protecting the patient from frictional tissue damage. Additionally, the outer cover provides a waterproof and stain resistant surface. For medical uses the outer cover may be made from an anti-microbial type material.

The cushioning device of the present invention allows a user in the field to adjustably set the maximum pressure level in each support cell of the zone. When surrounded by atmospheric air, the support system apparatus is configured to be self-inflating, self-adjusting, and does not require expensive pumps and control systems as required by other related “treatment products.” Also, since there are fewer moving parts in the present invention, maintenance and repairs are simple and reasonable in cost compared to the complex related art.

The cushioning device of the present invention can be used in combination with any support device where self adjusting dynamic pressure support of the person or patient is required. For example, these support devices may be incorporated into a mattresses, sofas, seats, etc.

Referring to FIG. 1, there is illustrated a perspective view of a cushioning device 10 in accordance with the present invention. The cushioning device 10 can be used in combination with any support device where self-adjusting dynamic pressure support of a person or patient 56 (FIG. 7) is required. For example, the support device may include a mattress, sofa, seat, etc. The cushioning device 10 includes a support system apparatus 12 may also comprise in addition to the at least three support zones 1A, 1B and 1C with at least one fluid cell 14 present in each zone having an tailored reactivity, optionally present are a sleeve apparatus 16, a jacket 18, and a topper cushion 20.

The support system apparatus 12 includes at least one support cell 14 in each zone (1A, 1B, 1C, etc.) for providing lifting support for a patient 56 and each operatively include an intake valve 40 and an exhaust valve 42 are operatively attached either directly or indirectly to each support cell 14 within the zone. As illustrated in FIG. 1, the cushion device 10 may also includes two end walls 24, 26, and two side walls 28, 30. The end walls 24, 26, and the side walls 28, 30 can be formed from a resilient material such as foam or rubber. The topper cushion 20 rests on top of the jacket 18 and provides further cushioning to a body. The topper cushion 20 can be composed of any resilient material, for example, foam, down feathers, an inflatable air cushion, etc.

FIG. 2 illustrates a top view of a support 80 having individually controllable zones A, B and C having a plurality of fluid cells in each zone. The support cells (14A-14H) including an envelope 34A-34C and a reforming element 32A-32C having different reactivities as shown in FIGS. 3-5. The lowering or reduction of the fluid volume 70 of the fluid cell 14 corresponds to an increased reactivity of the cell 14 under the same load. The envelopes 34A-34C may contain a fluid 36 having a fluid volume 70 where FIG. 3 has a greater fluid volume 70 that is associated with the torso section zone B of the patient than that of FIG. 4 that has a moderate fluid volume associated with the leg section zone C, and FIG. 5 further in comparison has the lowest fluid volume associated with head section zone A. The application of an external load on the envelope 34A-C causes the envelope 34A-C to deform into a compressed form, where envelope 34C compresses quicker under the same load because of a lower fluid volume. The reforming element 32A-32C provides a reforming force to the interior surface 38A-C of the envelope 34A-C. The reforming force causes the envelope 34A-C to return to its original form when the external load is removed from the envelope 34A-C.

The reforming elements 32A-C are preferably a resilient foam material, however, other resilient means can be used such as a coiled spring 500 (FIG. 10) or a bellows 520 (FIG. 11). The coiled spring 500 may be surrounded by a resilient material 502. The coiled spring 500 may be adjusted for reactivity by increasing the spring rate in zones where the supported weight is the greatest and decreasing the spring rate in the zones having the lowest supported weight. The bellows 520 may be formed from a pliable resilient material such as plastic and filled with a fluid such as air.

An example of a support system apparatus 12 for a mattress includes a plurality of support cells 14A, 14B, 14C, and/or 14D as illustrated in FIGS. 1 and 2. Intake valves (40A, 40B, 40C, 40D, 40E, 40F, 40G, and 40H) and exhaust valves (42A, 42B, 42C, 42D, 42E, 42F, 42G and 42H) are also illustrated in FIG. 2. Each intake valve 40 includes an intake check valve 48 allowing fluid 36 only to flow into the support cell 14, while preventing fluid 36 from flowing out of the support cell 14 that aids in the self-inflation of the mattress or support. Each exhaust valve 42 includes an exhaust check valve 50 allowing fluid 36 to flow out of the support cell 14, while preventing fluid 36 from flowing back into the support cell 14. Each exhaust valve 42 may be connected to a zone exhaust conduit 60 included in an exhaust control system 46. Each intake valve 40 may be connected to an intake conduit 58 included in an intake control system 44.

The intake control system 44 may be connected to a fluid supply reservoir 52 or directly to the atmosphere. The exhaust control system 46 may be connected to a variable restrictor (54A, 54B and 54C) or vented directly to the atmosphere to provided additional control of the reactivity of the zone to weight supported by the section. The variable restrictors (54A, 54B and 54C) may be used in addition to or in place of fluid cells having different fluid volumes 70 as the fluid volume once set is fixed, but the adjustable restrictors allow the patient to further fine tune the responsiveness of the zone. Generally, the fluid 36 included in the fluid supply reservoir 52 is air, however, any suitable fluid 36 (e.g. water or nitrogen) may be used. The fluid supply reservoir 52 may comprise an ambient source of fluid 36 such as atmospheric air.

As illustrated in FIG. 7, the weight of a body such as a patient 56 resting on the cushion device 10 deforms the envelope 34 in each support cell 14. The pressure of the fluid 36 within each envelope 34 increases as the volume of the envelope 34 decreases under deformation and cells with reduced fluid volume react faster and thus equalize in pressure faster. As the pressure of the fluid 36 increases, the fluid 36 in each envelope 34 flows out of the envelope 34 through a corresponding exhaust valve 42 and into the exhaust control system 46. Next, the fluid 36 may optionally flow from the exhaust control system 46 into the variable restrictor 54. Furthermore, as each envelope 34 deforms to conform to the irregular shape of the patient 56, the area of the envelope 34 supporting the load increases. Equilibrium is achieved when the forces within the envelope 34, including the pressure of the fluid within the envelope 34 multiplied by the area of the envelope 34 supporting the load, plus the force provided by the reforming element 32, equal the weight of the load.

As illustrated in FIG. 13 an individual zone controllable pressure relief valve 62 is included in the exhaust control system 46 and is attached to an end 64 of the exhaust conduit 60. The outlet 66 of the controllable pressure relief valve 62 is attached to a user accessible controller 63 that may consist of dials or other level setting devices. The controllable pressure relief valve 62 controls the maximum pressure level of the fluid 36 in the exhaust conduit 60 and in each envelope 34 in each support cell 14 in the selected zone. A rotatable knob 68 or other adjusting mechanism on the controllable pressure relief valve 62 allows a user to adjust the regulated maximum pressure level. The rotatable knob 68 may be electrically or mechanically connected to the pressure relief valve to control the release of pressure. Different selected maximum allowable pressures in the support cells 14 of zones 1, 2 and 3 allowing the support system apparatus 300 to accommodate patients 56 of different weights. Also, the setting of different maximum allowable pressures in the support cells 14A, 14B, and 14C allows different degrees of conformation between the patient 56 and the surface of each envelope 34. The maximum pressure may be set to ensure that the interface pressure under the entire contact surface of the patient 56 is below the pressure that may cause tissue damage. The cushioning device 300 of the present invention allows a user in the field to adjustably set the maximum pressure level in each support cell 14 within the zone. The maximum pressure may be above about 6 inches of water but a range of about 8 to 12 inches of water is satisfactory, but this range may be adjusted by +/−6 inches of water depending on operational requirements, user preferences, etc.

FIG. 7 illustrates the patient 56 resting on a mattress 72 segmented into three different zones for the head zone associated with pressure region PA, the torso zone associates with pressure regions PB and PC, and the leg zone associated with pressure regions PD and PE. High pressure regions on the patient 56 are indicated by the force arrows PA, PB, PC, PD, and PE. The head zone with pressure region PA has a considerable smaller pressure associated than the torso zone encompassing PB and PC. The head zone may be configured to have less open spaces or fluid zones as shown in FIG. 5 than the torso zone with fluid cells as shown in FIG. 3. The head zone with fluid cells having reduced fluid volume are more reactive to the lower weight of the head and thus are deemed to feel softer as the zone reaches the ideal interface pressure much faster than a fluid cell having a greater proportional fluid volume. The leg zone having a weight between the head zone and the torso zone may have a fluid cell as shown in FIG. 4 or a similary shaped cell having a different density foam.

FIG. 8 illustrates the patient 56 resting on a cushion device 10 of the present invention. As shown, the cushion device 10 provides a low uniform interface pressure PX that supports the entire contact surface of the patient 56. This interface pressure may be below the pressure that may cause tissue damage, thereby preventing the formation of pressure sores and other injuries.

As the weight of the patient 56 is removed from each support cell 14, the reforming element 32 (FIGS. 3, 4 and 5) in each envelope 34 exerts a reforming force on the interior surface 38 of each envelope 34. As each envelope 34 expands, a partial vacuum is created in the interior space or fluid volume 70 of each envelope 34. The vacuum draws the fluid 36 from the fluid supply reservoir or atmosphere 52 into the intake control system 44. Next, the fluid 36 is drawn from the intake control system 44 through a corresponding intake valve 40 into the interior space or fluid volume 70 of each envelope 34. When the fluid supply reservoir 52 and the fluid exhaust reservoir 54 comprise atmospheric air, inflation can be accomplished without the need for expensive blowers, pumps or microprocessors as required by previously available “treatment products.” The support system apparatus 12 of the present invention also has the ability to self-adjust every time a patient 56 moves, or is repositioned on, the support system apparatus 12. When the pressure distribution applied to the support system apparatus 12 changes, the support cells 14 within the support system apparatus 12 automatically inflate or deflate to restore the low interface pressure PX under the entire patient (FIG. 8).

Another embodiment of the present invention as illustrated in FIG. 1 and may be configured to provide for separately controlled support zones “A,” “B,” and “C” within the cushioning device 80. Each support zone “A,” “B,” and “C” includes at least one support cell 14. Each support cell 14 may have operably attached thereupon at least one intake valve 40 and at least one exhaust valve 42. As illustrated in FIG. 2, each intake valve 40A-40H may be connected to the intake control system 44. The exhaust valves 42A and 42B in zone “C” are connected to an exhaust control system 82. The exhaust valves 42C, 42D, 42E and 42F in zone “B” are connected to an exhaust control system 84. The exhaust valves 42G and 42H in zone “A” are connected to an exhaust control system 86. Each intake valve 40A-40H allows fluid 36 to flow into each support cell 14A-14H, respectively, while preventing fluid 36 from flowing back out of each support cell 14A-14H, respectively. Each exhaust valve 42A-42H allows fluid 36 to flow out of each support cell 14A-14H, respectively, while preventing fluid 36 from flowing back into each support cell 14A-14H, respectively. The intake control system 44 may be connected to the fluid supply reservoir 52 or the atmosphere. The exhaust control systems 82, 84, and 86 are shown to be connected to the fluid reactivity valve 54, which is an adjustable valve to either increase or decrease the rate at which the air exits the individual exhaust control system that is an option to control reactivity either replacing the fluid cells of different volume or in combination with allowing greater control. The larger the opening of the restriction of valve 54 is made then the softer that the individual zone feels because the zone equalizes pressure more quickly, but a minimal flow is required to allow pressure to vent. Adjustable restriction valve 54 always allows flow to exit from the exhaust control systems and only regulates that speed at which it exits the exhaust control system and may be placed before or after the valve. Generally, the fluid 36 included in the fluid supply reservoir 52 is atmospheric air, however, other fluids 36 can be used.

Each exhaust control system 82, 84, and 86 includes a pressure relief valve 88, 90, and 92, respectively, which maintains the pressure of the fluid 36 in zones “A,” “B,” and “C” below a selected level. A rotatable knob 68 or other adjusting system may be included in each pressure relief valve 88, 90, and 92 allows a user to set the maximum pressure level of the fluid 36 in each zone “A,” “B,” and “C.” A heavier patient 56 may require or want a higher minimum pressure to support their weight more comfortably. Also a heavier person may want a firmer and less reactive zone to prevent a feeling of “squishiness” from rapid loss of fluid and may adjust the fluid reactivity valve 54 to have a smaller opening and therefore slower reaction to the movement of a patient 56.

FIG. 3 illustrates a cross-sectional view of the support system apparatus 80 and zones “A” that is available with maximum fluid capacity and thus the slowest reacting. FIGS. 4 and 5 illustrate lower fluid volume cells “B,” and “C” that may be used in zones for quicker reactivity. Optionally a single pattern for the cells could be used and the density of the foam is changed to allow changes in fluid volume either by modifying the foam of either FIG. 3 or FIG. 5. When atmospheric pressure air is supplied to the fluid supply reservoir 52, there is no need for blowers or pumps to supply the pressurized fluid 36. Each support cell 14A-14H can self-inflate when the weight of the patient 56 is removed as described above for the support system apparatus 12. Each exhaust control system 82, 84 and 86 allows the maximum pressure level of the fluid 36 in each zone “A,” “B,” and “C” to be individually set. FIG. 13 illustrates an example of different pressure levels set in zones “1,” “2,” and “3.” For example, if the support system apparatus 80 is included in a mattress in a bed (not shown), a different level of pressure or firmness can be provided for the upper, middle, and lower portions of the patient's body 56.

FIG. 6 illustrates a cut-away perspective view of a mattress cushioning device 200 having three zones, with each zone having adjustable responsiveness and pressure controls. As shown, the fluid cells are arranged in different directions between zones and have different volumes and structures tailored to the portion of the body supported. The mattress cushioning device 200 includes a torso support system 220, a heel support system 240, and a sleeve apparatus 260, the jacket 18, the topper cushion 20, and the outer cover 22. The torso support system apparatus 220 includes a plurality of support cells 14 surrounded by cushioning edge pieces of the side wall 28, the end wall 26, and the side wall 30. The side walls 28 and 30 and the end wall 26 may be formed from a resilient material to prevent injury and for patient comfort. The sleeve apparatus 260 may include cell covers 96. Each cell may include a cover 96 that surrounds a support cell 14 to prevent sliding and frictional motion to be transmitted to the patient 56. The support cells 14 provide self-inflating and self-adjusting pressure support to the torso region of a patient 56 resting on the support system apparatus 220. The support cells 14 for the torso region extend in a longitudinal direction of the mattress cushioning device 200.

The heel support system apparatus 240 includes a plurality of support cells 14, the end wall 29, a side wall 242, and a side wall 244. The heel support system 240 provides support for the heel area of a patient 56. The support cells 14 extend in a transverse direction on the mattress cushioning device 200 at the head and foot zones.

The optional jacket 18 may surround the torso support system apparatus 220 and the heel support system apparatus 240 and the head support system. The topper cushion 20 lies on top of the jacket 18 and provides further cushioning and comfort to the patient 56. The topper cushion 20 may be composed of any resilient material, for example, foam, down feathers, an inflatable air cushion, etc. FIG. 9 shows a mattress 180 having three zones with different types of fluid cells in each of the zones, with the head zone 1 and foot zone 3 are one type of cells and the fluid cells of the torso zone 2 are as shown in FIGS. 14-19. The different type fluid cells allow for more fluid volume for the torso zone to allow for complete support for the heavier torso and quick responsiveness for the legs and head zones.

FIG. 9 shows an embodiment a body support apparatus 180 of the present invention using different types of fluid cells to adjust the reactivity of the individual zones. The individual zones of the apparatus 180 may be discretely controlled to manipulate the pressure on individual parts of a body 56 supported on the body support apparatus 180 as shown in FIG. 8. The body support apparatus 180 shown in FIG. 9 includes a plurality of self-inflating fluid cells shown in FIGS. 10, 11 and 16 that may be affixed together to form a support surface 12 such as shown with zone 2, a cutaway shown in FIG. 14, wherein each of said plurality of self-inflating fluid cells 14 has at least one port 46, an exterior 560, and an interior 562 (FIG. 16), and wherein said interior 562 is defined by an open area, or air space, for receiving fluid, which may be air. In addition, the body support apparatus 180 may have a harnessing system 36 shown in FIG. 14, or manifold system 30, that controls the direction and flow volume of air into the self-inflating fluid cells 14 such that the pressure in one or a group of the plurality of self-inflating cells may be discretely controlled. The harnessing system, or manifold system, 30 may be operatively attached to the ports of an interconnected group of self-inflating fluid cells of the plurality of self-inflating fluid cells.

The support system apparatus 12 may include at least one self-inflating fluid cell, or reforming element, 14 such as an air spring, pod, or cartridge, having a spring bias, 14 for providing lifting support and discrete manipulation of a patient 56. As shown in FIG. 15, the greater the number of fluid cells 14, the greater the dynamic response can be tailored to a heavier weight or load. The fluid cells 14 may be constructed such that several fluid cells 14 are utilized to form a matrix in the body support 12 to form an individual zone for heavier weights such as a torso of a patient 56 so that the body support 12 includes a sufficient number of fluid cells 14 to allow for manipulation of specific parts of the body or pressure on a specific part of the body. The ability to manipulate pressures on specific parts of the body on the support 12 is dependent on the number of fluid cells 14 that are present and will typically improve when the number of fluid cells 14 is increased with a heavier load. For example, there can be at least three fluid cells 14 across the portion of the support 12 which would support a person's back so that when the fluid cells 14 are manipulated, discrete control of pressure in the fluid cells 14 would transfer to discrete manipulation of pressure on the body on the support 12.

FIG. 20 illustrates a side view of a fluid cell 14 having a double helical pattern 530, a vertical rotational axis 540, and a single port 40. The fluid cells 14 may have a single helical pattern or a double helical pattern. However, the fluid cell 14 may also be any fluid cell which has a spring bias which effects the reformation of the fluid cell 14 such that the fluid cell 14 collapses when loaded with a load having a force which is greater than the sum of the forces within the fluid cell 14, including the pressure of the fluid inside the fluid cell 14 multiplied by the area of the fluid cell 14 supporting the load, plus the reforming force of the fluid cell 14, and said fluid cell 14 reforms when said load is reduced to a load having a force which is less than the sum of the force within the fluid cell and the reforming force of the fluid cell 14. In other words, the fluid cell acts as a reforming element such that once the fluid cell 14 is compressed with the weight of a person or article, the fluid cell 14 will reform when the weight is reduced. Equilibrium is achieved when the forces within the fluid cell, including the pressure of the fluid within the fluid cell multiplied by the area of the fluid cell supporting the load, plus the force provided by the spring bias of the fluid cell equal the weight of the load.

The application of an external load on the fluid cell 14 causes the fluid cell 14 to deform into a compressed form. The fluid cell 14 provides a reforming force which causes the fluid cell 14 to return to its original form when the external load is removed from the fluid cell 14. The fluid cell 14 may comprise a resilient material that can contain a fluid such as air, water or nitrogen. The fluid cell 14 may be formed from plastic or any elastomeric material that may be molded by convention processing techniques. The fluid cells 14 may be formed from foam or be constructed of a non-foam material.

A fluid cell 14 that contains air may be considered an air spring. The air spring 14 may be a cartridge that can be releasably attached, or quickly changed, by insertion and removal from a harnessing system 30. In this manner, if the air spring 14 needs to be changed, it can be done so with a friction slot or quick release mechanism.

The fluid cell 14 may have an exterior defined by folds along which the fluid cell collapses when loaded as described herein. For example, the fluid cell 14 could be a bellows 520 (FIG. 11) which is formed from a pliable resilient material such as plastic and filled with fluid such as air. The embodiment in FIG. 19 shows a cylindrical fluid cell 14 having a double or twin helix pattern 530. The double helix design 530 controls stability and deflection of the fluid cell 14 such that the fluid cell 14 closely maintains its alignment parallel to its vertical rotational axis 540 during compression and reformation a bellows does not have this stability because in a bellows each fold is separate (non-continuous) and therefore allows for independent reaction unlike the helix that has a continuous spiral surrounding the cell.

The air spring may have an external spring, but may also have an internal spring. The fluid cell 14 may include a coiled spring 500 (FIG. 10) which is surrounded by a resilient material 502 as a surface cover. The surface cover 502 may be fabric, waterproof material, rubber, plastic, moisture wicking material, microfiber, or any material which would resiliently or yieldingly cover the spring and be resiliently or yieldingly supported by the spring 500. An alternative to changing the volume of the air is to increase the thickness of the spring to control the rate of compression because of a higher rate spring 500.

In addition, the fluid cell may be restrained by an entrapment device 550 which restrains the expansion of at least one of the plurality of self-inflating fluid cells 14. An embodiment of an entrapment device is shown in FIGS. 17, and 18. The entrapment device 550 may be a strap constructed of fabric, plastic, rubber, leather, or any material that would restrict the movement of the fluid cell 14. Similarly, the entrapment device 550 may be any device which restricts the expansion of the fluid cell. A body support apparatus 12 may contain one or more fluid cells 14 that are restrained from applying pressure to a body on the body support and some fluid cells 14 that are not restrained, and thus free to be used to manipulate the pressures on the body. Restraining one or more cells would allow the unrestrained cells to adjust more quickly because the effective fluid volume of the zone has been reduced because lower fluid cell volume reacts to the patient's weight, which would allow the body support 12 to respond more rapidly to changes in pressure for lighter weight patients.

The firmness of the fluid cells may be controlled by adjusting the height of the fluid cell 14, the diameter of the fluid cell 14, the wall thickness of the fluid cell 14, the type of resin used to form the fluid cell 14, and the pitch or angle of the helix coupled with the OD and ID radius of the helix. In addition, the harnessing system 30, which allows control of the flow direction and volume, contributes to controlling the firmness of the fluid cells 14.

FIG. 20 and FIG. 21 show an embodiment provided so that each fluid cell 14 may have a multiple port air distribution system 140 which has multiple connections or ports 40A, 40B, 40C, 40D incorporated in, or integral to, the fluid cell 14 and can control intake flow, outflow, sound and speed of fluid movement. Alternatively, the multiple port air distribution system 140 may be connected to a single port 46 on the fluid cell 14, and include a T-plex, 3-plex, or 4-plex connector which allows the connecting lines which are a part of the harnessing system 30 to be attached to the fluid cell 14 in a variety of configurations as shown in FIG. 19. The ports may also be controlled to modify the cell reactiveness by having more ports open for a lighter patient for quicker fluid release and fewer ports open for heavier patients. The intake check valve 42 allows fluid to flow into the fluid cell 14, while preventing fluid from flowing out of the fluid cell 14. An adjustable flow restrictor 44 may be included in the exhaust port 40B to control the volume of air flowing tlirough the exhaust port tailored to the individual's weight. In addition, the multiple port air distribution system 140 may include one or more ports that allow the bilateral flow of fluid 40C, 40D. These ports may be included on the fluid cell 14 and be capped to prevent fluid exchange if fluid exchange is not desired for that location of the fluid cell 14 in the harnessing configuration.

The embodiment shown in FIG. 21 shows four ports: an intake port 40A having a check valve 42, an exhaust port 40B having a flow restrictor 44, and two open ports 40C, 40D which allow the bilateral flow of fluid, in or out of the fluid cell 14. The open ports 40C, 40D may be connected to a constant pressure or the atmosphere. Although the ports shown in FIG. 21 are positioned equidistant from each adjacent port, the ports may be positioned at any distance from one another.

FIG. 21 also shows that the multiple port air distribution system 140 may include a sound control batten 48 in the ports that allow fluid to flow in either direction 40C, 40D. The sound control batten 48 is for reducing the sound during intake and exhaust of the fluid cell 14. The sound control batten 48 can be reticulated foam, a variegated surface, or any material that would fit within the port or a conduit or connection extending from the port and function to reduce the sound of air movement during intake and exhaust. In addition, the sound control batten 48 may be formed from a flexible or rigid material.

The body support, or cushioning device 12 may includes a harnessing system 30 that controls the direction and flow volume of air into the self-inflating fluid cells 14 such that the pressure in one or a group of the plurality of self-inflating cells may be discretely controlled in the zone. The fluid cells 14 may be rotatable about a vertical axis 540 such that they may rotate in the casing 20 to allow them to be connected with the harnessing system 30 in various harnessing configurations. For example, the fluid cells 14 can be aligned such that the ports 40 are set at a 45 degree angle to the edge of the support apparatus 12. In addition, the harnessing system 30 may be releasably attached to the fluid cells 14 such that a plurality of harnessing configurations is possible. More specifically, the conduits, or connecting lines, 36 of the harnessing system 30, may be released from the ports 40 to which they are attached in a first harnessing configuration and reattached to another port on the same or another fluid cell 14 to create a second harnessing configuration. The harnessing system 30 allows for inflow of air to the fluid cell for reinflation speed and controllable and directional flow of air from the fluid cell 14.

Each self-inflating fluid cell may have an inlet port 40A and an exhaust port 40B as shown in FIGS. 20 and 21 or a single port 46 connected to a T-plex, 3-plex, or 4-plex connector on a connecting line 36 as shown in FIGS. 14, 16-21. The fluid cells may be connected in series to form one or more pressure zones. As shown in FIG. 13 a controllable pressure relief valve 88 may be operatively attached to the exhaust port 40B of at least one of the fluid cells 14 in each pressure zone. In addition, a check valve 43 may be located between the exhaust port 40B and the controllable pressure relief valve 88 such that once fluid flows out of the series or zone of fluid cells 14, the fluid may not flow back into that series or zone of fluid cells. Thus, fluid flows from a first fluid cell in a series of fluid cells, and continues though each cell in the series until the pressure in the fluid cells is equal to the pressure set by the controllable pressure relief valve 88 within the zone. The fluid cells may be connected, or harnessed, in multiple configurations depending on the needs of the patient.

In addition, FIG. 21 shows that some of the fluid cells 14 may be connected to an inlet check valve 42 or an exhaust check valve 43 and some of the fluid cells may contain open ports such as 40C and 40D. The releasability of the harnessing system 30, and the various configurations of the multiple port air distribution system 140 allow the system to be customized for different patients of different weights. FIG. 9 shows an example of a support system apparatus 180 where zone 2 of the mattress includes a plurality of fluid cells 14AA, 14BB, 14CC, 14DD, 14EE, 14FF, 14GG, 14HH, 14II, 14JJ, 14KK, 14LL, 14MM, 14NN, 14OO, 14PP, 14QQ, 14RR, 14SS and 14TT as illustrated in FIG. 9. The fluid cells in zone 2 may be held together by a holding mechanism or base housing 20 which is adapted to receive the fluid cells 14CC-14RR. The base housing may be a foam casing, plastic webbing, or any configuration that affixes the fluid cells together to form a mattress, seat, or sofa construct. FIG. 15 shows a base housing 20 that is a foam casing including bays 22 for receiving the fluid cells 14. The base housing 20 is composed of air or foam or other porous or non-porous materials. The base housing 20 functions as a fluid cell receiver and is a means of affixing the fluid cells 14 together to form a mattress or other body support construct. The base housing 20 provides fluid cell 14 stability by utilizing variable heights of the base, by altering the ILD, density and air pressure of the mass of the base housing (not limited to foam), and the relationship of base material to the number of fluid cells 14 in a given area. The base housing supports, houses, and prevents movement of the fluid cells 14 and the harnessing system 30.

FIG. 19 shows a side view of the base housing 20 with another manner in which the fluid cells 14 may be installed, whereas FIG. 15 shows a side view of the base housing 20 for use with the helix shaped cells without any of the fluid cells 14 installed. The base housing 20 in the foam embodiment of FIG. 19 can be made of various heights (H). For example, the fluid cells 14 can extend vertically significantly higher than the base housing. Conversely, the base housing foam 20 can extend vertically up to, or near to, the same height as the fluid cell 14. In order to hold the fluid cell 14 within the base housing 20, the base housing 20 can include threaded constructs 24 in various openings to receive a threaded (i.e., helical) exterior of the fluid cells 14.

FIG. 14 shows another embodiment of a zone comprising a casing 20 having a plurality of pads. At least one of the pads, in this embodiment the top pad, or first pad, 26, is adapted to accept the plurality of fluid cells within the zone. For example, as shown in FIG. 15, the pad includes openings or bays 22 that generally conform to the shape of the fluid cells 14 and secure the fluid cells 14 during use of the apparatus 12. The casing 20 may have one or more side walls 28, and a bottom pad, or second pad 27 located on a separate side of the fluid cells 14 than the top pad, or first pad, 26.

FIG. 15 shows that the support system apparatus 12 may have a topper cushion 50 and an outer cover 52. The topper cushion 50 rests above of the fluid cells 14 and base housing 20 to provide further cushioning. The topper cushion 50 may be formed from a layered fiber filled material, foam, wool, a moisture wicking material, or any other suitable material that provides cushioning. The base housing 20, fluid cells 14, harnessing system 30, and topper cushion 50 are contained by an outer cover 52 which has a low friction and low shear surface for further protecting the patient from frictional tissue damage. Additionally, the outer cover 52 provides a waterproof and stain resistant surface. The outer cover 52 can be expandable, waterproof, or moisture wicking. For medical uses, the outer cover 52 can be made from an anti-microbial type material.

An embodiment of the invention in FIG. 1 shows a support or cushioning device 10 having adjustable pressure relief zones A, B and C. The three or more pressure zones may have an adjustable pressure relief valve 88 operatively attached to each of the at least three pressure zones as shown in FIG. 2. Each of the pressure zones has at least one cell 14 having a first effective fluid volume 70 within the envelope 34. The fluid volume 70 of the cell 14 includes all of the gasses that are within the cell 14 that may be removed from complete compression of the envelope 34. When the fluid volume 70 is lower than the fluid volume 70 in an identically sized envelope 34 it is more reactive when the same load or weight 56 is placed onto the envelope 34. The support 10 is then talorable to specific weight in each zone by having at least one cell 14 having a second effective fluid volume 71 greater than said first effective fluid volume 70 within the at least three pressure zones 1, wherein the greater effective fluid volume 71 is associated with supporting a greater load 56 associated with that said zone 2 from a person. The support 10 may further comprise a cover or jacket 18, wherein said cover 18 surrounds all of the pressure zones 1, 2, or 3.

The support 10 may further comprise a reforming element 32, wherein the element 32 is a structure that is compressible under a load 56 and then returns to the original shape when the load 56 is removed. The reforming element 32 may have different shapes to create a different effective volume 70 in each of the at least three pressure zones to create the first effective fluid volume 70 and the second effective fluid volume 71. The support 10 may have fluid cells with different reactivities to loads 56 where the reforming element 32 is modified to have a different density 73 within each pressure zone 1, 2, or 3. The reforming element 32 can have fewer air holes 70 by either changing the material from for example foam to a material such a feathers or polyurethane fibers having a different amount of trapped air or the foam can have the density modified by increasing or decreasing the amount of air holes during processing of the foam reforming element 32.

Each pressure zone 1, 2, or 3 may have a pressure indicator 600, 601, 602 to allow the user to determine the proper P.S.I. setting for their comfort. The support 10 may further comprise a reforming element 32 positioned within each pressure zone 1, 2, or 3, wherein said first pressure zone 1 and said second pressure zone 2 has an equal cell volume and wherein the pressure zone supporting more weight is configured to have the reforming element 32 having a greater fluid displacement than the pressure zone 1 configured for less weight 56. The pressure zone 1 configured for supporting a lighter weight 56 has less fluid volume 70 and thus displaces the required fluid to support a patient 56 faster than a cell with more fluid volume 70.

The support 80 as displayed in FIG. 2 may further comprise an inlet valve 40 on each of the fluid cells 14 in the pressure zones 1, 2, or 3. The inlet valve 40 may also contain a check valve 41 that prevents back flow of fluid 36 from the cell into the manifold to prevent over pressuring of adjacent fluid cells 14 if pressured by the load of the patient 56.

The support 80 may further comprise a first density reforming element 32D producing a first fluid volume 70 within one of the at least three pressure zones 1, 2 or 3 and a second density reforming element 32E producing a second fluid volume 71 within one of the at least three pressure zones 1, 2 or 3, wherein the second volume 71 is greater than the first volume 70 and wherein the greater volume is configured to support a greater weight. The greater volume may be produced by having more and larger air spaces in the foam reforming element and thus a greater fluid volume reforming element is of a lower density than the reforming element having a higher density.

The support 180 may further comprise a plurality of cells 14 in each pressure zone. FIG. 9 displays pressure zone 2 that includes a plurality of cells for example 14CC, 14DD, 14EE, 14FF, 14GG, 14HH, 14II, 14JJ, 14KK, 14LL, 14MM, 14NN, 14OO, 14PP, 14QQ and 14RR. The plurality of cells 14 may contain a plurality of reforming elements 32 or 500 positioned within said plurality of cells 14, wherein said cells 14 are interconnected and forms an average fluid volume 70 in each pressure zone 1, 2 or 3. The reactivity of pressure zones 1, 2 or 3 may be controlled by increasing or decreasing the number of cells per unit of area so that the removal of a fluid cell 14 would decrease the average fluid volume 71 of pressure zone 1, 2 or 3 and thus making it more responsive to a lower weight.

A mattress 300 comprising a first pressure zone 1 having a first cell volume 310, a second pressure zone 2 having a second cell volume 320, and a third pressure zone 3 having a third cell volume 330. The cell volumes 310, 320, 330 are configured to correspond to a weight of a patient 56 supported by that pressure zone 1, 2, or 3, wherein heavier weights correspond to greater fluid volume in that zone. The cell volumes 310, 320, 330 can be controlled by increasing or decreasing the open spaces 70 as shown in FIGS. 3-5, or by changing only the density of the foam between identically shaped reforming elements 32. A dial 68 is then positioned to be operatively attached to each of the pressure zones 1, 2, or 3 to adjust an individual zone pressure. A pressure relief valve 88 may be attached to the dial 68 to control the maximum pressure.

The mattress 300 may have fluid cells 14 that further comprises an intake check valve 40 in each of the pressure zones 1, 2, or 3 or cells within the zone. The mattress 300 may also contain a support element 32 positioned within fluid cell 14 within each pressure zone 1, 2, or 3 to compensate for different weights 56 supported by each pressure zone 1, 2, or 3 to create a support surface for the mattress 300 that is responsive to the weight 56 supported by the pressure zones 1, 2, or 3. The mattress 300 in alternative may further comprise a cell reforming element 32, 500, 502, 520 positioned within the fluid cells 14.

A mattress 300 as shown in FIG. 13 may comprise a first pressure zone 1 having a first fluid volume 310. A second pressure zone 2 having a second fluid volume 320 that may have a different volume than the first fluid volume, which may comprise a plurality of cells 14 within a casing or body support apparatus 12 as shown in FIG. 14. A third pressure zone 3 having a third fluid volume 330 may be different than the volume of the first pressure zone 1 and second pressure zone 2. The mattress 300 has an adjustable pressure valve 88 constructively attached to each of said pressure zones 1, 2, or 3.

A resilient border or side wall 28 may surround said pressure zones 1, 2, or 3 to cover any ducting and manifolds that are connected between the fluid cells 14 and the pressure valves 88, 90, 92. A cover or topper cushion 20 encompassing said border 28 and said pressure zones 1, 2, or 3. The mattress 300 may further comprise a plurality of cells 14 within the pressure zones 1, 2, or 3 as shown in FIG. 9. The mattress 300 may include an intake manifold attached to each cell 14 within each pressure zone 1, 2, or 3 as shown in FIG. 2. Furthermore, an exhaust manifold 82, 84, 86 may be attached to each cell 14 within each pressure zone 1, 2, or 3, wherein the exhaust manifold 82, 84, 86 is operatively attached to the adjustable pressure valve 88, 90, 92.

The mattress 10, as shown in FIG. 1 may further comprise a first plurality of cells 14 within the first pressure zone 1 having a first size 1A, and a second plurality of cells 14 within the second pressure zone 2 having a second size 1B, and a third plurality of cells 14 within the third pressure zone 3 having a third size 1C, wherein the first fluid volume 70 is less than the second 71 and third 72 fluid volumes and wherein the pressure zone 1, 2, or 3 with the largest cells 14 has the greatest fluid volume 70 and bears the greatest weight 56.

One of the difficulties of sleep is that as a person tosses and turns at night, their body pressure on the mattress or contact surface changes. Studies show that 85% of people sleep on their side. If such a person should shift during the night to their back, the surface area contacting the mattress would increase causing a decrease in pressure between the body and the mattress. However, the pressure on the heels would increase. Curvy people would tend to have less surface contact. The head may have a different pressure need than the body and heels. A persons head would normally be on a pillow which spreads out the surface contact area. A person sleeping on their back would have a greater pressure on their heels due to the small surface area.

An advantage of this system is that air pumps and compressor may be used but are not needed for adjusting the pressure in the zones. That is they are non-powered without pumps and function to maintain a constant pressure based on the cracking pressure of the dials on the pressure relief valves.

A pressure relief valve is a type of valve used to limit or control the pressure in a system. The pressure is relieved by allowing the pressurized fluid to flow from the valve out of the system. In this case when the pressure setting on the dial 68 is exceeded, the relief valve becomes the path of least resistance and the valve is forced open and only a portion of the fluid is diverted. Once the pressure reaches the re-sealing pressure set by the dial 68, the valve will re-close. An example is about 32 mmHg or 0.5 psi in the air cells regardless of the body weight.

The mattress 10 may further comprise a foam reforming element 32 may be positioned to substantially fill alternating cells 14 within each pressure zone 1, 2, or 3, such as shown in FIG. 5. For example in FIG. 9, a reforming element could be placed into fluid cells 14CC, 14EE, 14GG, 14II, 14KK, 14MM, 14PP and 14RR so that the zone would be more reactive because a lower effective fluid volume for the zone would be present. Whereas, fluid cells 14DD, 14FF, 14HH, 14JJ, 14LL, 14NN, 14OO and 14QQ could contain the maximum volume of fluid such as shown in FIGS. 11 and 16 or a spring 500 as shown in FIG. 10. The fluid cells 14CC-14RR may be combined into a single pressure zone 1, 2, or 3 with a harnessing system 30 so that all fluid cells 14 may have an identical internal fluid pressure set by a pressure relief valve 68.

The mattress zone 80 may further comprise a common intake manifold 30 on all cells 14 within each of the pressure zones 1, 2, or 3. There may be a common exhaust manifold on all cells 14 within each of the pressure zones 1, 2, or 3, wherein the exhaust manifold 88, 90, 92 in each zone is attached to the adjustable pressure valve 68 as shown in FIG. 2. Each zone may be connected to a variable restrictor valve 54 to fine tune the reactivity of the fluid cell to the individual 56 on the support 80.

A support surface 200 as shown in FIG. 6 may comprise at least three zones 210, 220, 240 forming a support surface for a patient 56. The support surfaces has at least two different fluid cell volumes in the at least three zones, wherein the at least two different fluid cell volumes 70, 71 of the zone 210, 220, 240 that is proportional to the weight 56 the fluid cell 14 supports, wherein a greater weight 56 is supported by a greater fluid cell volume 70. The support surface 200 has an adjustable pressure regulator 68 on each of the at least three zones 210, 220, 240.

Another embodiment of the support surface 500 that is self-inflating as shown in FIG. 22 comprises a first zone 501 having a port 560 on each cell 514, a conduit 582 attached to said ports 560, said conduit 582 is operatively attached to an intake check valve 540 and a pressure relief valve 588. The conduit 582 is attached to the ports 560 on the fluid cells 514 allows for two-way travel of the fluid between all the cells below the pressure set by the pressure relief valve 588. When a cell 514A is compressed the excess fluid 536 is transferred to adjacent cells 514A if the pressure is below the set point of the pressure relief valve 588. If the pressure of the fluid 536 in the conduit 582 is above the set point of the pressure relief valve 588 the fluid is released from the conduit 582. Optionally attached to the pressure relief valve 588 is a variable restriction 554. The variable restrictor 554 controls the time it takes to release the excess fluid 536 above the pressure set point. To prevent the mattress from being reacting too slowly with lighter loads, such as when a head of a patient rests upon the zone 501, then the restrictor valve 554 may be opened to form a greater sized orifice to prevent it from feeling too stiff or closed to a smaller orifice to prevent slow reactiveness of the cells if the patient moves too much.

The support surface 500 has second zone 502 having an intake check valve 540 on each cell 514B, and an exhaust port or check valve 560 on each cell 514B that is attached to a common exhaust manifold 582, said exhaust manifold 582 operatively attached to a pressure relief valve 588, wherein the second zone 502 is operatively positioned with respect to said first zone 501. As shown in FIGS. 22 and 23 the second zone 502 may have the cells 514B oriented in the same or different directions than adjacent zones 501 and 503. In addition to the zones 502 being oriented differently than each other they may also have a fluid cell 514 having a different effective fluid volume per square inch than a fluid cell 514 in a different zone. The effective fluid volume per square inch of the fluid cell 514 can be controlled by varying the density of the reforming element or by adjusting the amount of free space not occupied by the reforming element within the fluid cell 514.

The support apparatus 500 has a third zone 503 having a port 560 on each cell 514 and a conduit 582 attached to each said port 560. The conduit 582 is operatively attached to an intake check valve 540 and a pressure relief valve 588 that are attached to the same or common conduit 582. The third zone 503 is operatively positioned with respect to said second zone 502. The third zone 503 is plumbed similarly to the first zone 501 in that the fluid 36 that leaves a compressed cell 514 enters an under-pressured cell 514 that aids in the process of reforming the attached fluid cell within the zone 503 more quickly and fluid above the set pressure level is vented from the conduit 582.

The support surface 500 has a first fluid cell volume 570 associated with at least one of said zones 501, 502, 503 and a second fluid cell volume 571 associated with at least one of said zones 501, 502, 503. The second fluid cell volume 571 is greater than said first fluid volume 570 and wherein second fluid volume supports a greater load per square inch of a surface of said zone. The greater fluid volume in the fluid cell 514 may be provided to support heavier loads such as the torso of a patient resting on the surface 500 more comfortably such as zone 502. The fluid volume is calculated in the amount of a fluid, such as air, present in the fluid cell 514 per square inch of the fluid cell to allow for size difference corrections. Generally the fluid cells 514 having the greatest load carrying capacity also have the greatest fluid volume, but all fluid cells may be identical and the release of the fluid 536 with a variable restrictor 554 may be used to tailor the fluid cell responsiveness to load. The support surface 500 may have a knob attached to each said pressure relief valve 588 that would allow the pressure relief setting to either be raised or lowered to accommodate either lighter or heavier than normal or average patients.

Another embodiment of the support surface 500 that is self-inflating is shown in FIG. 23 that comprises a modified pneumatic connection between zones 501, 502, 530. The surface 500 also comprises a first zone 501 having a single port 560 on each cell 514. A first conduit 580 is attached to each of the ports 560 so that they all receive identical pressure. The first conduit 580 is operatively attached to an intake check valve 540 and a pressure relief valve 588 and is independent of the other zones 502, 503. The first zone 501 may be associated with the patients head and neck, which may be the lightest load produced on a zone 501, 502, 503 from a resting body and therefore requiring less fluid to be replaced during body movement as less fluid has been displaced from the fluid cell 514.

The support surface 500 has a second zone 502 having an intake check valve 540 directly attached onto each fluid cell 514, and a port 560 on each cell that is attached to a second conduit 581. The second conduit 581 is operatively attached to a pressure relief valve 588 that controls the maximum pressure within the connected fluid cells 514. The second zone 502 is operatively positioned with respect to said first zone 501 to form the support surface.

The fluid cells 514 in the second zone 502 are configured to support the heavier load of the torso of a patient by having two fluid refill entry points to quickly refill the fluid cell 514 that also may be configured to have a greater fluid volume 571 than fluid cells 514 in other zones. The intake check valve 540 allows one-directional flow into the cell 514 of fluid 536 from the atmosphere that is drawn by a partial vacuum produced by the reforming element such as a spring, foam or bellows when it returns the fluid cell 514 to a normal configuration after a load is removed. The port 560 allows two-way flow so that under load fluid exits the port 560 and when unloaded allows the port 560 receives pressurized fluid from a loaded cell 514 attached to the conduit 581 that is compressed by the patient. The pressure from the connected cell 514 is used to refill the cell 514 to the maximum set internal pressure, which may be greater than the internal force provided by the reforming element because of the use of a leveraged pumping action between the connected cells 514 within the zone 502.

The support surface 500 has a third zone 503 having a single port 560 on each cell 514 that allows two-directional flow of fluid 536 to the cell. A third conduit 583 is attached to each of the ports 560 allowing equalization of pressure within the zone 503 of all the fluid cells 514. The conduit 583 is operatively attached to an intake check valve 540 and a pressure relief valve 588. The third zone 503 is operatively positioned with respect to said second zone 502 that is positioned to form a patient surface.

A conduit crossover 584 with a crossover check valve 548 allows one-way flow from the third conduit 583 to the second conduit 582. The crossover conduit 584 allows crossover flow to the second conduit 582 and may refill the fluid cells 514 if their cell pressure is below a pressure relief set point of each of the pressure relief valves 588 of the second 581 and third conduit 583. The crossover conduit 584 allows one-way directional flow only from the third zone 503 that is configured for a lighter weight to the center zone 502 designed to support the heavier torso portion of the patient. The crossover conduit 584 forms a natural pumping action between zones that allows for a firmer mattress feel in the torso zone 502 by refilling fluid cells 514 quicker without resorting to pumps that may break, be noisy, fail during power loss or continuously consume power.

The support surface 500 may further comprise a reforming element 570 positioned in each fluid cell 514, wherein said reforming element 570 may be configured to have at least two different fluid cell volumes, wherein the at least two different fluid cell volumes 570, 571 of the zone is proportional to the weight the fluid cell 514 supports, wherein a greater weight (load) is supported by a greater fluid cell volume 571.

The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in light of the above teaching. For example, the cushioning device of the present invention is suitable for providing self-inflating, self-adjusting, zoned pressure control, and alternating pressure support to any supported body. Also, the cushioning device of the present invention is suitable for any application where low interface pressure is required between the cushioning device and the surface of the body being supported. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims. 

1. A support having adjustable pressure relief zones comprising: at least three pressure zones; an adjustable pressure relief valve operatively attached to each of the at least three pressure zones; at least one cell in a first zone having a first effective fluid volume; and at least one cell in a second zone having a second effective fluid volume adjustable to greater than said first effective fluid volume, wherein the greater effective fluid volume is associated with supporting a greater load associated with that said zone.
 2. The support of claim 1 further comprising: a reforming element, wherein said element has a different volume in each of the at least three pressure zones to create the first effective fluid volume and the second effective fluid volumes.
 3. The support of claim 1 wherein the reforming element has a different density within each pressure zone.
 4. The support of claim 1 further comprising: a reforming element positioned within each pressure zone, wherein said first pressure and said second pressure zone has an equal cell volume and wherein the pressure zone supporting more weight is configured to have the reforming element having a greater fluid displacement than the pressure zone configured for less weight.
 5. The support of claim 1 further comprising: an inlet valve on each of the pressure zones.
 6. The support of claim 5 further comprising: a check valve associated within each of the inlet valves.
 7. The support of claim 1 further comprising: a cover, wherein said cover surrounds the pressure zones.
 8. The support of claim 1 further comprising: a first density reforming element producing a first volume within one of the at least three pressure zones; and a second density reforming element producing a second volume within one of the at least three pressure zones, wherein the second volume is greater than the first volume and wherein the greater volume is configured to support a greater weight.
 9. The support of claim 1 further comprising: a plurality of cells in each pressure zone; and a plurality of reforming elements positioned within said plurality of cells, wherein said cells are interconnected and forms an average fluid volume in each pressure zone.
 10. A mattress comprising: a first pressure zone having a first cell volume; a second pressure zone having a second cell volume operatively positioned with respect to said first pressure zone; a third pressure zone having a third cell volume operatively positioned with respect to said second pressure zone; and a dial positioned on each of the pressure zones to adjust an individual zone pressure.
 11. The mattress of claim 10 further comprising: an intake check valve in each of the pressure zones.
 12. The mattress of claim 10 further comprising: a pressure relief valve attached to the dial to control the maximum pressure.
 13. The mattress of claim 10 further comprising: a support element positioned within the each pressure zone to compensate for different weights supported by each zone to create a support surface for the mattress that is responsive to the weight supported by the zone.
 14. The mattress of claim 10 further comprising: a cell reforming element positioned within the fluid cells.
 15. A mattress comprising: a first zone having a first fluid volume; a second zone having a second fluid volume operatively positioned with respect to said first zone; a third zone having a third fluid volume operatively positioned with respect to said second zone; an adjustable pressure valve in each of said zones; a resilient border surrounding said zones; and a cover encompassing said border and said zones.
 16. The mattress of claim 15 further comprising: a plurality of cells within each of the zones; an intake manifold attached to each cell within each said zone; and an exhaust manifold attached to each cell within each said zone, wherein the exhaust manifold in each cell is attached to the adjustable pressure valve.
 17. The mattress of claim 16 further comprising: a first plurality of cells within the first zone having a first size, wherein the first fluid volume is less than the second and third fluid volumes; a second plurality of cells within the second zone having a second size; and a third plurality of cells within the third zone having a third size, wherein the zone with the largest cells has the greatest fluid volume and bears the greatest weight.
 18. The mattress of claim 17 further comprising: a reforming element positioned in alternating cells within each zone.
 19. The mattress of claim 18 further comprising: a common intake manifold on all cells within each of the zones; and a common exhaust manifold on all cells within each of the zones, wherein the exhaust manifold in each zone is attached to the adjustable pressure valve.
 20. A support surface comprising: a first zone having a port on each cell, a conduit attached to said ports, said conduit operatively attached to an intake check valve and a pressure relief valve; a second zone having an intake check valve on each cell, and an exhaust check valve on each cell that is attached to a common exhaust manifold, said exhaust manifold operatively attached to a pressure relief valve, wherein the second zone is operatively positioned with respect to said first zone; a third zone having a port on each cell, a conduit attached to each said port, said conduit operatively attached to an intake check valve and a pressure relief valve, wherein the third zone is operatively positioned with respect to said second zone; a first fluid cell volume associated with at least one of said zones; and a second fluid cell volume associated with at least one of said zones, wherein said second fluid cell volume is greater than said first fluid volume and wherein second fluid volume supports a greater load per square inch of a surface of said zone.
 21. The support surface of claim 20 further comprising: a reforming element.
 22. The support surface of claim 20 further comprising: a knob attached to each said pressure relied valve.
 23. A support surface comprising: a first zone having a single port on each cell, a first conduit attached to said ports, said first conduit operatively attached to an intake check valve and a pressure relief valve; a second zone having an intake check valve on each cell, and a port on each cell that is attached to a second conduit, said second conduit operatively attached to a pressure relief valve, wherein the second zone is operatively positioned with respect to said first zone; a third zone having a single port on each cell, a third conduit attached to each said port, said conduit operatively attached to an intake check valve and a pressure relief valve, wherein the third zone is operatively positioned with respect to said second zone; and a conduit crossover check valve allowing one way flow from the third conduit to the second conduit, wherein crossover flow to the second conduit refills fluid cells if cell pressure is below a pressure relief set point of each of the pressure relief valves of the second and third conduit.
 24. The support surface of claim 23 further comprising: a reforming element positioned in each fluid cell, wherein said reforming element is configured to have at least two different fluid cell volumes, wherein the at least two different fluid cell volumes of the zone is proportional to the weight the fluid cell supports, wherein a greater weight is supported by a greater fluid cell volume. 